Activation In Anterior Prefrontal Cortex Research Articles

Frontal Control Over Automatic Emotional Action Tendencies Predicts Acute Stress Responsivity

BackgroundThe ability to control social-emotional actions is relevant for everyday social interaction and may be indicative of responsiveness to actual social stress situations. This is particularly relevant for predicting stress responsiveness of the hypothalamic-pituitary-adrenal axis, known to be dysregulated in various stress-related affective disorders. Here we tested, in a large sample, whether reduced frontal control over social approach-avoidance actions can indeed signal increased hypothalamic-pituitary-adrenal axis reactivity to subsequent social stress exposure. MethodsA total of 279 subjects (214 men) participated in a functional magnetic resonance imaging social-emotional approach-avoidance task that involved impulsive and controlled emotional actions. Subsequently, participants underwent a stress induction including a socially evaluated cold pressor task and a mental arithmetic task. Salivary cortisol and α-amylase levels, as well as self-reported negative affect, were measured before and after stress induction. ResultsEmotion control was successfully induced by the approach-avoidance task. Namely, instrumental overriding of automatic social approach-avoidance actions was associated with the typical increased bilateral anterior prefrontal cortex activation, longer reaction times, and more errors. Moreover, subsequent stress induction led to significant increases in all stress measures. Critically, bilateral anterior prefrontal cortex activation during emotion control was associated with reduced responses to the subsequent stressor in not only cortisol but also α-amylase and negative affect. ConclusionsThe ability to recruit prefrontal regions during social-emotion regulation predicts cortisol responses to an actual social stress situation. This finding provides the first evidence that instrumental control over social approach avoidance actions can signal stress responsiveness in major stress systems, providing a promising biomarker in stress vulnerability and resilience research relevant for affective disorders.

In silico vs. Over the Clouds: On-the-Fly Mental State Estimation of Aircraft Pilots, Using a Functional Near Infrared Spectroscopy Based Passive-BCI.

There is growing interest for implementing tools to monitor cognitive performance in naturalistic work and everyday life settings. The emerging field of research, known as neuroergonomics, promotes the use of wearable and portable brain monitoring sensors such as functional near infrared spectroscopy (fNIRS) to investigate cortical activity in a variety of human tasks out of the laboratory. The objective of this study was to implement an on-line passive fNIRS-based brain computer interface to discriminate two levels of working memory load during highly ecological aircraft piloting tasks. Twenty eight recruited pilots were equally split into two groups (flight simulator vs. real aircraft). In both cases, identical approaches and experimental stimuli were used (serial memorization task, consisting in repeating series of pre-recorded air traffic control instructions, easy vs. hard). The results show pilots in the real flight condition committed more errors and had higher anterior prefrontal cortex activation than pilots in the simulator, when completing cognitively demanding tasks. Nevertheless, evaluation of single trial working memory load classification showed high accuracy (>76%) across both experimental conditions. The contributions here are two-fold. First, we demonstrate the feasibility of passively monitoring cognitive load in a realistic and complex situation (live piloting of an aircraft). In addition, the differences in performance and brain activity between the two experimental conditions underscore the need for ecologically-valid investigations.

F10. Linking Emotional Control and Stress Reactivity: Anterior Prefrontal Cortex Activation During Emotion Control Predicts Cortisol Response After Stress Induction

The ability to control social emotional actions is relevant for everyday social interaction and may be predictive of actual stress-responsiveness during social stress. Here we tested whether these processes are indeed interrelated, hypothesizing that reduced frontal control over emotional actions is associated with an increased cortisol response after subsequent stress induction.

Stress, coping, executive function, and brain activation in adolescent offspring of depressed and nondepressed mothers

ABSTRACTThis study examined the associations among chronic stress, activation in the prefrontal cortex (PFC), executive function, and coping with stress in at-risk and a comparison sample of adolescents. Adolescents (N = 16; age 12–15) of mothers with (n = 8) and without (n = 8) a history of depression completed questionnaires, neurocognitive testing, and functional neuroimaging in response to a working memory task (N-back). Children of depressed mothers demonstrated less activation in the anterior PFC (APFC) and both greater and less activation than controls in distinct areas within the dorsal anterior cingulate cortex (dACC) in response to the N-back task. Across both groups, activation of the dorsolateral PFC (DLPFC; Brodmann area [BA9]) and APFC (BA10) was positively correlated with greater exposure to stress and negatively correlated with secondary control coping. Similarly, activation of the dACC (BA32) was negatively correlated with secondary control coping. Regression analyses revealed that DLPFC, dACC, and APFC activation were significant predictors of adolescents’ reports of their use of secondary control coping and accounted for the effects of stress exposure on adolescents’ coping. This study provides evidence that chronic stress may impact coping through its effects on the brain regions responsible for executive functions foundational to adaptive coping skills.

The Importance of Knowing When You Don't Remember: Neural Signaling of Retrieval Failure Predicts Memory Improvement Over Time.

Just as the ability to remember prior events is critical for guiding our decision-making, so too is the ability to recognize the limitations of our memory. Indeed, we hypothesize that neural signaling of retrieval failure promotes more accurate memory judgments over time. To test this hypothesis, we collected longitudinalfunctional magnetic resonance imaging data from 8 to 9 years olds, 10 to 12 years olds, and adults, with two time points spaced approximately 1.4 years apart (198 scan sessions in total). Participants performed an episodic memory retrieval task in which they could either select a response or report uncertainty about the target memory detail. Children who engaged anterior insula more strongly during inaccurate or uncertain responses exhibited greater longitudinal increases in anterior prefrontal cortex activation for decisions to report uncertainty; both of these neural variables predicted improvements in episodic memory. Together, the results suggest that the brain processes supporting effective cognitive control and decision-making continue to develop in middle childhood and play an important role for memory development.

Genetic variants in oxytocin receptor and arginine-vasopressin receptor 1A are associated with the neural correlates of maternal and paternal affection towards their child

There is extensive evidence in animal studies, particularly in vole species (Microtus), that oxytocin (OT) receptor and arginine-vasopressin (AVP) receptor 1a is critical for the regulation of maternal and paternal behavior, respectively. Human studies have gained insight into the relationship between both hormone receptor gene variants and behavior, but not between the variants and the underlying brain activity. To study this, we investigated the association between neural activation of the anterior prefrontal cortex (APFC) in mothers and fathers in response to their child smiling video stimuli to induce the positive affect related to attachment with their child, and genetic variants of OT receptor (OXTR) and AVP receptor 1A (AVPR1A). Overall, 43 mothers and 41 fathers participated, and each parent's child smiling was video recorded. Participants were then genotyped and underwent near-infrared spectroscopy to measure neural activation of the APFC while observing their own child smiling compared with an unfamiliar child. We found that the right inferior APFC was activated in response to child video stimuli in mothers and differential hemispheric activation of the inferior APFC in OXTR rs2254298-G/G mothers compared with -A carrier mothers, but not in fathers. Furthermore, we found a difference in the left inferior APFC activation between AVPR1A RS3-non-334 and -334 carrier fathers, but not mothers. Our results indicate a sex-dependent association between the genetic variants and the inferior APFC activations of maternal and paternal positive affect, analogous to the results reported in voles.

Context Memory Decline in Middle Aged Adults is Related to Changes in Prefrontal Cortex Function.

The ability to encode and retrieve spatial and temporal contextual details of episodic memories (context memory) begins to decline at midlife. In the current study, event-related fMRI was used to investigate the neural correlates of context memory decline in healthy middle aged adults (MA) compared with young adults (YA). Participants were scanned while performing easy and hard versions of spatial and temporal context memory tasks. Scans were obtained at encoding and retrieval. Significant reductions in context memory retrieval accuracy were observed in MA, compared with YA. The fMRI results revealed that overall, both groups exhibited similar patterns of brain activity in parahippocampal cortex, ventral occipito-temporal regions and prefrontal cortex (PFC) during encoding. In contrast, at retrieval, there were group differences in ventral occipito-temporal and PFC activity, due to these regions being more activated in MA, compared with YA. Furthermore, only in YA, increased encoding activity in ventrolateral PFC, and increased retrieval activity in occipital cortex, predicted increased retrieval accuracy. In MA, increased retrieval activity in anterior PFC predicted increased retrieval accuracy. These results suggest that there are changes in PFC contributions to context memory at midlife.

The impact of age on prefrontal cortex integrity during spatial working memory retrieval

Healthy aging is accompanied by a decline in spatial working memory that is related to functional cerebral changes within the spatial working memory network. In the last decade, important findings were presented concerning the location (e.g., prefrontal), kind (e.g., ‘underactivation,’ ‘overactivation’), and meaning (e.g., functional deficits, compensation) of these changes. Less is known about how functional connections between specific brain regions are affected by age and how these changes are related to behavioral performance. To address these issues, we used functional magnetic resonance imaging to examine retrieval-related brain activation and functional connectivity in 18 younger individuals and 18 older individuals. We assessed working memory with a modified version of the Corsi Block-Tapping test, which requires the storage and reproduction of spatial target sequences. Analyses of group differences in brain activation and functional connectivity included comparisons between younger individuals, older individuals, older high-performers, and older low-performers. In addition, we conducted a functional connectivity analysis by using a seed region approach. In comparison to younger individuals, older individuals showed lower right-hemispheric dorsolateral prefrontal activation and lower functional connectivity between the right dorsolateral prefrontal cortex and the bilateral orbitofrontal cortex. Older high-performers showed higher right dorsolateral and anterior prefrontal cortex activation than older low-performers, as well as higher functional connectivity between these brain regions. The present results suggest age-related reductions of prefrontal activation during spatial working memory retrieval. Moreover, task-related functional connectivity appears to be lower in older adults. Performance accuracy in older adults is associated with right dorsolateral and anterior prefrontal cortex activation, and with the functional connection between these regions.

Cognitive inflexibility in obsessive-compulsive disorder and major depression is associated with distinct neural correlates.

Obsessive-compulsive disorder (OCD) and major depressive disorder (MDD) are frequently co-morbid, and dysfunctional frontal-striatal circuits have been implicated in both disorders. Neurobiological distinctions between OCD and MDD are insufficiently clear, and comparative neuroimaging studies are extremely scarce. OCD and MDD may be characterized by cognitive rigidity at the phenotype level, and frontal-striatal brain circuits constitute the neural substrate of intact cognitive flexibility. In the present study, 18 non-medicated MDD-free patients with OCD, 19 non-medicated OCD-free patients with MDD, and 29 matched healthy controls underwent functional magnetic resonance imaging during performance of a self-paced letter/digit task switching paradigm. Results showed that both patient groups responded slower relative to controls during repeat events, but only in OCD patients slowing was associated with decreased error rates. During switching, patients with OCD showed increased activation of the putamen, anterior cingulate and insula, whereas MDD patients recruited inferior parietal cortex and precuneus to a lesser extent. Patients with OCD and MDD commonly failed to reveal anterior prefrontal cortex activation during switching. This study shows subtle behavioral abnormalities on a measure of cognitive flexibility in MDD and OCD, associated with differential frontal-striatal brain dysfunction in both disorders. These findings may add to the development of biological markers that more precisely characterize frequently co-morbid neuropsychiatric disorders such as OCD and MDD.

Default mode network activity in schizophrenia studied at resting state using probabilistic ICA

Alterations in brain function in schizophrenia and other neuropsychiatric disorders are evident not only during specific cognitive challenges, but also from functional MRI data obtained during a resting state. Here we apply probabilistic independent component analysis (pICA) to resting state fMRI series in 25 schizophrenia patients and 25 matched healthy controls. We use an automated algorithm to extract the ICA component representing the default mode network (DMN) as defined by a DMN-specific set of 14 brain regions, resulting in z-scores for each voxel of the (whole-brain) statistical map. While goodness of fit was found to be similar between the groups, the region of interest (ROI) as well as voxel-wise analysis of the DMN showed significant differences between groups. Healthy controls revealed stronger effects of pICA-derived connectivity measures in right and left dorsolateral prefrontal cortices, bilateral medial frontal cortex, left precuneus and left posterior lateral parietal cortex, while stronger effects in schizophrenia patients were found in the right amygdala, left orbitofrontal cortex, right anterior cingulate and bilateral inferior temporal cortices. In patients, we also found an inverse correlation of negative symptoms with right anterior prefrontal cortex activity at rest and negative symptoms. These findings suggest that aberrant default mode network connectivity contributes to regional functional pathology in schizophrenia and bears significance for core symptoms.

Neural correlates of reality monitoring during adolescence

BackgroundReality monitoring processes serve the critical function of discriminating between externally derived information and self-generated information. Several reality monitoring studies with healthy adult participants have identified the anterior prefrontal cortex (PFC) as consistently engaged during the recollection of self-generated contextual cues. Furthermore, reduced activity of medial PFC has been linked with schizotypal trait expression of delusion and hallucination-like symptoms in healthy adults undergoing fMRI reality-monitoring tasks. The present study seeks to examine the cerebral underpinnings of reality monitoring during adolescence, a developmental stage where the expression of schizotypal traits may increase risk for psychosis. MethodA group of 33 adolescents, assessed using the Schizotypal Personality Scale (SPQ), underwent fMRI while performing a reality monitoring task. After an encoding session where the subject or the experimenter read out a series of complete or incomplete word pairs, subjects were presented with the first word of studied word pairs and asked whether the corresponding word had been: (1) perceived or produced (context monitoring), or (2) read by the subject or by the experimenter (origin monitoring). ResultsAnalyses revealed a common set of activated brain areas during both context and origin monitoring conditions. When compared to context monitoring, origin monitoring was associated with greater activation in anterior PFC within Brodmann area 10 (BA 10). Correlation analyses revealed that reduced signal change in BA 10 during origin monitoring was associated with greater schizotypal trait expression. ConclusionMuch like adults performing a similar reality monitoring task, adolescents exhibit a common pattern of brain activity during origin and context monitoring, with functional specialization within the prefrontal cortex involving preferential activation of BA 10 during origin monitoring. Greater schizotypal trait expression appears to be significantly associated to reduced BA 10 activity during origin monitoring trials. Results are discussed in relation to cortical specialization within the PFC and trait expression during adolescence.

Reduced anterior prefrontal cortex activation in young binge drinkers during a visual working memory task

Working memory (WM) is a major cognitive function that is altered by chronic alcohol consumption. This impairment has been linked to alterations in the hippocampus and prefrontal cortex (PFC). Animal and human studies have shown that the adolescent brain is more sensitive to the neurotoxic effects of alcohol than the adult brain, particularly those structures that mature late on in development, such as the hippocampus and prefrontal brain. The aim of the present study was to assess visual working memory and its neural correlates in young university students who partake in intermittent consumption of large amounts of alcohol (binge drinkers). A sample of 42 binge drinkers and 53 corresponding control subjects performed an identical pairs continuous performance task (IP-CPT) in a combined event-related potential (ERP) and exact low-resolution brain electromagnetic tomography (eLORETA) study. The results revealed that, despite adequate performance, binge drinkers showed a smaller late positive component (LPC) associated with hypoactivation of the right anterior prefrontal cortex (aPFC) for matching stimuli, in comparison with control subjects. These findings may reveal binge drinking-related functional alteration in recognition working memory processes and suggest that impaired prefrontal cortex function may occur at an early age in binge drinkers.

Neural correlates of retrieval processing in the prefrontal cortex during recognition and exclusion tasks

Event-related fMRI was employed to contrast the neural activity elicited in prefrontal cortex during recognition memory and exclusion tests. The study phases preceding each memory test were identical, involving the presentation of study items (visually presented words) in one of two study contexts. For the recognition test subjects were required to respond positively to all old items regardless of study context, and to respond negatively to new items. For the exclusion task, positive responses were required to old items presented in one of the study contexts only; negative responses were required both to unstudied items and studied items from the alternative context (non-targets). No prefrontal region demonstrated greater activity for new items in the exclusion task. Thus, there was no evidence that retrieval cues were processed differently according to the specificity of the sought-for information. In several regions, most notably bilateral anterior prefrontal cortex, activity was greater for old than for new items regardless of task. Activity in right dorsolateral prefrontal cortex was also greater for old than for new items; these effects however were larger in the exclusion task. The findings are consistent with previous reports that activity in anterior prefrontal cortex elicited by recognition retrieval cues is sensitive to retrieval success, and extend these findings to the exclusion task. The findings for the right dorsolateral cortex add further weight to the proposal that this region supports post-retrieval monitoring of retrieved information.

Right Anterior Prefrontal Cortex Activation during Semantic Monitoring and Working Memory

Areas of the adult human brain used for semantic monitoring were identified using positron emission tomography. For a series of tasks, subjects viewed a list of familiar English nouns and monitored the words for names of dangerous animals. The monitoring task used here also contained an instruction to keep track of the number or percentage of targets for report after the scan. Surface characteristics of the tasks such as stimulus rate, number of targets, and whether subjects were asked to count or estimate the number of targets were varied across multiple conditions within and between subjects. A passive word viewing condition was used as the control in all subjects. Reliable activations were identified in anterior and dorsalrightprefrontal cortex [Brodmann areas (BA) 9 and 10] andleftextrastriate cortex. The right prefrontal cortical locations are similar to areas that have been activated during many episodic memory tasks. This surprising finding led to a thorough review of the literature for examples of other activations within 16-mm vector distance of this right prefrontal area. Activations in the vicinity of right BA10 due to episodic memory retrieval, to various forms of working memory, and to miscellaneous tasks were found. The right prefrontal activations in the current experiment and the additional working memory and miscellaneous tasks demonstrate that, although right BA10 is routinely activated by episodic retrieval tasks, it is not uniquely activated by episodic retrieval tasks.